A question about an Icelandair flight..

Yes, they will alight the first plane and a while later board another plane after having gone through a passport check.

Yes they have to deplane. However, I don't think it allows time to get anything to eat. Every time I have flown through Iceland, we have basically walked off one plane, gone through passport control, and straight to our gate to board the next plane. They really have a pretty awesome system. It is designed so that all these planes arrive about the same time, everyone shuffles, and off you go. One time passport control had issues and was backed up. Almost everyone thought they would miss their flight...nope. All the planes were held until everyone got through passport control. The most they will be able to do is maybe grab a quick snack out of store (if there is time).

The problem with grabbing a quick snack is everyone else just got off a plane and are trying to do it too. We tried once to "grab and go" but found the lines too long. Maybe with travel down a bit they will be more fortunate.

My question is: will they actually get off that first plane, have to go into the airport, then reboard a different plane?

Yes

will they be able to get something to eat in the airport,

May have time to grab a pre-made sandwich, but would not plan for "sit and eat " meal

It’s been a few years since we’ve flown Seattle to Paris via KEF, however I remember that even though our connection was short, we still had time to grab a sandwich and snacks for the next leg. It’s quite an efficient operation there, everything is close and compact, no hard slogs down long corridors.

If food is an issue, your friends should plan ahead. I like Icelandair, but food is not its strong point unless your friends qualify for the SAGA lounge. They can preorder food for the flight if desired. Also, even if there is time for a grabbing a quick snack, it will not be an inexpensive snack! My first priority would probably be to use the restroom between planes and I would simply pack a lunch.

I've transferred flights twice in Keflavik and it is quite impressive how well organized everything is.

Thank you! Most helpful.

We had time to grab a bit to eat. And were not dressed for 34 degrees.

Food resembles in the terminal and in the plane: skyr, sandwich, ....

I did a quick search of Icelandair flights and it's likely they'll have to switch planes and gates, but the airport is very small and everyone is basically doing the same thing. As others have said it's possible they will have time to grab something to eat, but there are pretty limited choices airside, especially if you're in the C or D terminals (see the map here). Though my destination was Iceland (no transfer) I found it easy to order food from Icelandair ahead of time. Here's the current list of menus though you might note that in economy there are limited options for flights from Vancouver and other west coast cities. It was ok food, but next time I'd pack my own sandwich and snacks.

*edited to clarify Frank's accurate pointing out that there's only one terminal at the airport. I meant gates. It was early.

Icelandair and Keflavik airport are so efficient at these changes because it is a major part of their operations. They get off the plane, go through immigration (they enter Schengen in Iceland), and then get on the next plane.

Once going through I was asked if I was staying or going. Another time nothing was said and my passport was stamped. Everybody speaks English.

I agree there might be time to grab a bite to eat but not enough to sit down for a meal.

The good news for them is no passport control in Paris. That is really a blessing.

Thank you all.
My friends thank you too!